Biotransfer of heavy metals along a soil-plant-insect-chicken food chain: field study.

The accumulation and transfer of Pb, Zn, Cu, and Cd along a soil-plant-insect-chicken food chain at contaminated sites were investigated. The study site nearing the Pb/Zn mine had been contaminated by heavy metals severely. Cadmium and Pb concentrations steadily declined with increasing trophic level (p < 0.01), but concentrations of Zn and Cu slightly increased from plant to insect larva (p > 0.05). The concentrations of heavy metals were the highest in chicken muscle, with lower values in liver and blood. The bioaccumulation of Pb was observed in chicken livers. The eliminations of Pb, Zn, Cu, and Cd via insect and chicken feces avoid metal bioaccumulation in insect and chicken body. These results suggest that the accumulation of heavy metals in specific animal organ of tissues could not be neglected, although transfer of metals to chicken from plant and insect was limited.